Alkylation of cyclic hydrocarbons



ALKYLATION OF CYCLIC HYDROCARBONS y Filed April 29,` 1944 Patented Apr. 29, 1947 l y" ALKYLATION F CYCLIC HYDRGCARBONS Roland B. Day, Riverside, Ill., assigner to 'Universai Oil Products Company, Chicago, Ill., a corporation o! Delaware Application April 29, 1944, Serial No. 533,312 Claims'. (UL 2GB-671) This application is a continuation-impart of my co-pending application Serial No. 476,665, illed February 22, 1943.

This invention relates to the alkylation of an higher molecular weight oleflns are used. I have also found that lower temperatures can be employed if olens having more than one double bond per molecule are used in the catalyst prepalkylatable cyclic hydrocarbon. and is more spe- 5 aration. cincally directed to the use of a particular cata- My invention is readily adaptable to the alkyllyst comprising an aluminum chloride hydroation of cyclic hydrocarbons such as aromatic carbon complex having an unusually high achydrocarbons including benzene, toluene, etc., or tivity and selectivity for the desired reaction. alicyclic hydrocarbons COIltaining at least 5 car- It is well known in the prior art that metal bon at'oms in the ring such as methyl cyclopenhalide catalysts of the Friedel-Crafts type such tane, cyclohexane, etc., with alkylating agents as aluminum chloride promoted with a hydrogen including olefins or alkyl halides such as propyl halide are highly effective in accelerating the rechloride, tertiary butylchloride, etc.. and is paraction between cyclic hydrocarbons such as aroticularly suitable for the alkylation of benzene matics with various oleilns to forml alkyl arol5 with ethylene to produce ethylbenzene. The latmatics, ter hydrocarbon has become an important raw It has also been shown that various aluminum material for the production of synthetic rubber chloride-hydrocarbon complexes Isuch as those since it can be readily dehydrogenated to form formed by reacting aluminum chloride with an styrene which is subsequently polymerized with aromatic hydrocarbon or by reacting aluminum 2o butadiene to form high molecular weight polychloride with a paraillnic hydrocarbon have submers having physical properties resembling those stantial activity for various hydrocarbon conof natural rubber. Various'other alkyl aromatics version reactions. y such as isopropylbenzene which arev employedv as l have discovered that a catalyst having a high blending agents in aviation gasolines, may be degree of activity and selectivity may be obtained formed by the process of my invention. 'by reacting aluminum chloride with an olefin The process of my invention may be conducted hydrocarbon providing the aluminum chloride in various ways, the most feasible being the use content of the resulting complex is maintained of a mechanically agitated reaction zone in which within the range of about 60 to about 85 weight the preformed catalyst contacts the hydrocarper cent of the complex. p bon reactants followed by the removal of the re- In one embodiment the present invention comaction product to suitable separating equipment prises a process for the alkylation of an alkylatwherein the desired reaction product is separated able cyclic hydrocarbon which comprises subfrom the unconverted material, the latter being jecting a mixture of said hydrocarbon and an recycled to the reaction zone. The alkylation alkylating agent under alkylating yconditions to reaction is carried out by introducing a mixture the action of an aluminum chloride hydrocarbon of the desired cyclic hydrocarbon and alkylating complex formed by reacting aluminum chloride agent, the former'being in substantial molar exwith an oleilnic hydrocarbon and having an cess of the latter, into the reaction zone containaluminum chloride content calculated as A1203 ing the liquid catalyst and relatively small within the range of about 60 to about 85 weight 0 amounts of a hydrogen halide, said reactionzone per cent of the complex. being maintained at a temperature of from about The catalyst of my invention may be prepared 0 to about 250 F. under pressure sufficient to by interacting the requisite amount of aluminum maintain the hydrocarbon in a substantially liqchloride in the presence of a hydrogen halide or uid phase, a substance affording some hydrogen halide un- The amount of hydrogen halide ordinarily emder the conditions of preparation, thereby formployed is of the order of about 0.5 to about 10 and ing a mobile dark red or brownllquid which can preferably from about 1.0 to 3.0 mol per cent of be pumped readily into the reaction zone. When the hydrocarbon reactants. In order to maintain lower boiling oleflns such as ethylene are used, the aluminum chloride concentration in the comthe preparation may suitably be carried out at plex between the desired limits of 60 to about 85 temperatures within the range of 100 to 250 F. weight per cent, a small portion of fresh comand under superatmospheric pressure. The templex may be continually added or a regulated perature of the catalyst preparation is dependent portion of the spent catalyst may be withdrawn to a certain extent upon the type of olefin emfrom the reaction Zone, passed through a heating ployed, lower temperatures being utilized when zone into a chamber containing granular aluminum chloride to replenish the aluminum chloride in the complex and thereafter recycling the complex to the reaction zone.

The operating details and the method of conducting the process of my invention are more clearly set forth in the description of theaccompanying diagrammatic drawing which illustrates in conventional side elevation one type of apparatus in which the objects of the invention may be accomplished.

For simplification the description f the drawing has been restricted to a reaction wherein benzene is alkylated with ethylene. However, it is not intended that this restriction place any undue limitation on the broad applicability of my invention.

Referring to the drawing, the charging stock in the present instance, benzene is admitted into the system through line containing valve 2 into pump 3 and discharged through line 4 containing valve 5, commingled with ethylene and hydrogen chloride obtained as hereinafter set forth, and the mixture introduced into alkylation Y zone 6 wherein the alkylation of the benzene with the ethylene is accomplished in the presence of a preformed aluminum chloride hydrocarbon complex having an aluminum chloride content calculated as A1203 in between about 60 to about 85% by Weight of the complex. The molar ratio of benzene to ethylene may be maintained within the range of 2 to about 2O and preferably between about 3 to about 8. Zone 6 consists preferably of a mechanically agitated reaction zone containing, for example, a stirring device 1 operated by motor 8. Obviously, however, any other apparatus which is effective for producing intimate contact between the liquid catalyst and the hydrocarbon reactants may be employed. Alkylation zone 6 may' be equipped with suitable cooling means not shown in order to control the exothermic alkylation reaction. The reaction products from. zone 6 are directed through line 9 containing valve I0 into settler II wherein the catalyst is separated from the hydrocarbon reaction products. The catalyst thus separated is withdrawn from settler I I through line 45 containing valve 46 into pump 41. The discharge from this pump is split into two streams, the ifrst lof said streams passing through line 61 containing valve 68 and thereafter into alkylation zone 6. The remaining portion is directed through line 48 containing valve 49 into heat exchanger 5U and thereafter through line 5| containing valve 52 into aluminum chloride chamber 53.

Chamber 53 comprises an aluminum chloride supply zone containing therein a bed of solid granular aluminum chloride. By passing regulated portions of the spent catalyst from settler through the granular aluminum chloride bed in chamber 53 and recycling this stream through line 54 containing valve 55 into reaction zone 6,

the aluminum chloride concentration of the catalyst in said reaction zone can be easily maintained within the desired range of 60 to 85% by weight of the complex. The initial charge of catalyst formed by reacting aluminum chloride with ethylene in the presence of hydrogen chloride is introduced into the system through line 56 containing valve 51 into pump 58 which discharges through line 59 and valve 61 into line 54 through which it is passed to reaction zone 6. However, the initial catalyst charge may be formed in situ by placing the requisite amount of aluminum chloride into the reaction zone and passing ethylene and hydrogen chloride through the zone until the AiCls is converted into the complex. The respective amounts of catalyst sent through chamber 53 and by-pass line 69 are regulated in a manner such that the aluminum chloride concentration of the total catalyst in reaction zone 6 is maintained within the desired range concentration.

The hydrocarbon reaction products from zone 6 are withdrawn from settler Il through line I2 containing valve I3 into pump I4 and are directed to line I5 containing valve I6 into column l1 wherein the hydrogen chloride employed as a promoter for the alkylation reaction is separated from the hydrocarbon reaction products. separated hydrogen chloride is removed overhead through line 43 containing valve 44 and recycled to the alkylation zone. The reaction products comprising ethyl benzene, a small amount of polyethylated benzene and unconvertedl benzene are withdrawn through line I8 containing valve I9 into pump 2D which discharges through line 2I containing valve 22 into column 23 wherein the unconverted benzene is separated from the remaining hydrocarbons.l The unconverted benzene is removed overhead through line 34 containing valve 10 and passes through condenser 35, line 36 into receiver 31. Pump 40 takes suction on receiver 31 through line 38 containing valve 39 and recycles the unconverted benzene to the system through line 4I containing valve 42. The bottoms of column 23 comprising ethylbenzene and minor proportions of more highly alkylated benzenes are withdrawn through line 24 containing Valve 25 into pump 26, discharged through line 2.1 and valve 28 into fractionating column 26 wherein the ethylbenzene is removed overhead through line 30 containing valve 3|, cooled, condensed and recovered as a product of the reaction. The more highly alkylated benzenes are withdrawn through line 32 containing valve 33 and may be recovered/as a product of the reaction or may be further treated, for example, in a dealkylation operation, admixing the polyalkylated benzenes with benzene and contacting the mixture with a dealkylation catalyst such as silicaalumina to further augment the yield of the ethylbenzene. The original charge of hydrogen chloride is introduced through line 60 containing valve 6| into line 43 through which it passes into alkylation zone 6 in admixture with the benzene and ethylene charged to the alkylation zone. Ethyleneis introduced into the system through line 62 containing valve 63 into pump 64 which discharges throughline 65 containing valve 66 into line 4 wherein it is commingled with the benzene charge as hereinbefore set forth. A portion of the spent catalyst withdrawn from settler |I may be removed from the system through line 1I containing valve 12 and thereafter treated to recover the aluminum chloride and hydrocarbons contained therein. By removing a portion of the v spent catalyst through line 1| and replacing the removed portion of the catalyst by freshly prepared catalyst through line 56, the aluminum chloride concentration in the alkylation zone may be maintained at the desired level.

The following examplesillustrate the commercial utility and feasibility of this invention. However, it is not intended that .the broad scope of the invention be limited to the exact operating conditions hereinafter set forth.

Example I An AlCls-hydrocarbon complex was prepared by reacting the AlCls with ethylene in the pres- The ence of hydrogen chloride. A dark red mobile vcomplex was formed having an AlClz content (determined as A1203) of about 75 weight per cent. 'I'his catalyst is used for the alkylation of benzene with ethylene in a system comprising a mechanically agitated reaction zone of the turbo mixer type, a settling zone, means for recycling the catalyst, a part of which is contacted with aluminum chloride to maintain the concentration in the reaction zone, and a ractionating system for recovering desired products from the hydrocarbon reaction products.

A mixture of benzene and ethylene (molar ratio of benzene to ethylene :1) is heated to 150 F., commingled with about 3 mol per cent of hydrogen chloride and introduced into the reaction zone containing the catalyst previously mentioned. The products fromthe reaction zone indicate that about 96 mol per cent of the ethylene reacts with the benzene to form ethylbenzene.

Example II Example III When repeating Example I using the same charging stock and operating conditions but a catalyst containing 60% of aluminum chloride (calculated as A1203) the amount of alkylation f is very low, the yield of ethylbenzene being about 12 mol per cent of the ethylene charge, and most of the remaining ethylene being polymerized to form high boiling polymers.

I claim as my invention:

1. A process for the alkylation of an alkylatable cyclic hydrocarbon which comprises subjecting an alkylatable cyclic hydrocarbon and an alkylating agent under alkylation conditions to the action of a catalyst comprising an aluminum chloride-hydrocarbon complex formed by the inter- .action of aluminum chloride and an aliphatic olefin and having an aluminum chloride concentration above 60 but below 85 weight per cent of the complex.

2. A process for the alkylation of an aromatic hydrocarbon which comprises subjecting an aromatic hydrocarbon and an oleiin under valkylation conditions to the action of a catalyst com- 6 prising an aluminum chloride-hydrocarbon complex formed by the interaction of aluminum chloride and an aliphatic olefin and having an aluminum chloride concentration above but below weight per cent of the complex'.

3*. A process for alkylating an aromatic hydrocarbon with an olefin comprising subjecting an aromatic hydrocarbon and an olenn in the presence'of hydrogen chloride at a temperature within the range of about 0 to about 250 F. and in substantially liquid phase to the action of a catalyst comprising an aluminum chloride-hydrocarbon complex formed by the interaction of aluminum chloride and an aliphatic olen, said complex having an aluminum chloride concentration aboveV 60 but below 85 weight per cent.`

4. A process for producing ethylbenzene which comprises subjecting benzene and ethylene under alkylation conditions to the action of a catalyst comprising an aluminum chloride-hydrocarbon complex formed by the interaction of aluminum chloride and an aliphatic olefin, said complex having an aluminum chloride concentration above 60 but below 85 weight per cent.

5. A process for producing ethylbenzene which comprises alkylating benzene with ethylene in a reaction zone containing a catalyst comprising a preformed aluminum chloride-hydrocarbon complex formed by the interaction of aluminum chloride and an aliphatic olefin in the presence of hydrogen chloride, said catalyst having an aluminum chloride concentration above 60 but below 85 weight per cent of the complex, withdrawing a portion of said catalyst from said reaction zone, contacting at least a portion of said withdrawn catalyst with aluminum chloride to dissolve aluminum chloride therein, and thereafter returning a suiilcient portion of catalyst containing aluminum chloride dissolved therein to the reaction zone -to maintain the aluminum chloride concentration of the complex in the reaction zone at above 60 and below 85 weight per cent.

ROLAND B. DAY.

REFERENCES CITED The following references are of record in the `file of this patent:

UNITED STATES PATENTS 

